In projectors, which are often also referred to as digital projectors, the light modulator can be illuminated time-sequentially with light of different colours from different wavelength ranges in order to generate partial images time-sequentially so quickly that a viewer can then only perceive them temporally superimposed as a multicoloured image. In order to generate the different colours time-sequentially, a light source unit can for example be provided with several light sources, which emit light from different wavelength ranges and thus with different colours sequentially in time. The image generation by means of a projector is then limited to the colours of the light sources.